Fluid-operated swab



Dec. 9, 1930.

H. w. FLETCHER 1,784,096

FLUID OPERATED SWAB Filed July 23, 1929 [Lu-old 11v VENTOR ATTORNEY i Patented Dec. 9, 1930 1 UNITED STATES; PATIENT, OFFICE HAROLD w. rmcnm, or nous'rou, TEXAS, assxelvo'a ro nuemss frooL- coMrANY, or nousron, TEXAS, a conrona'rrou or exas a rLuln-ormnm Application filed Jul as, 1929. amino. 380,349.

My invention relates to the construction of fluid operated swabs. In a prior co-pending application for patent by myself jointly with Norman H. Kicker filed October 20, 1928, Serial No. 313,742 is shown a swab of the same general construction as that forming the subject matter of this invention.

I contemplate an improvement on the prior structureto avoid the closure of the valve through the force of air from below when the plunger is dropping in its travel.

I find that the valve in the swab plunger tends to drop open when the plunger reaches the upper limit of its stroke, thus allowing the plunger to fall in the rising blast of air following the liquid discharge. But where the lower side of the valve and the end of the valve stem are not protected, and the preponderance of air pressure below the plunger is high, the air discharge will tend to force the valve closed so that the plunger will not fall. I have devised a structure for the plunger which will enable the plunger to fall and the valve to stay open in spite of the dynamic pump. The lower end is reduced and threaded at 3 to engage the upper threaded socket upon the head. The inner face of the body has downwardlyconverging walls 4 to obtain a stream-line effect in the falling of the plunger.

I The head member 2 has its upper end 5 of the same outer diameter as is the body. The

upper end 5 is in fact a ring threaded on to the body at 3 and having its lower end 6 beveled downwardly and outwardly, thus forming the seat of the valve when it is closed. Below the ring 5 is a valve recess 7 formed in the head and spaced from the ring a suitable distance by connecting legs 8. I contemplate the use of three legs 8, but the number is immaterial. Thus between the ring and the valve seat are upwardly inclined passages 9 for the fluid from below the plunger.

The valve recess 7 is formed inthe countersunk orrecessed upper end of thehead 2, thus leaving a short run or walllO around the edge of the valve, when'the valve is open, to deflect the fluid away from the valve. The headis of smaller outer diameter and has an, axial opening 11 for the valve stem 12, and the valve recess 7 is tapered downwardly to this opening. At the lower end of thehead 2 the diameter is reduced to form an end 13 in which openings Mareformed to communicate with the small chamber 15 below the lower end of the valve stem.

The valve 17 at the upper end of the stem 7 is shaped to fit the recess 7 on its lower side,

and on its upper side it is shaped to fit the seat 6 and is curved upwardly to a point 18, thus producing a stream-line upper face offering small resistance to the passage of fluid through the openings 9 into the swab body.

In the use of my improved swab the plunger has a seat in the pump barrel, not show'n,where'in theair pressure is introduced below the lower end of the head 2. When the air enters below the swab it enters the open 1 ings 14' belowthe valve stem and forces the valve into its upper seat 6, thus closing the openings 9 and lifting'the swab with its load of liquid u wardly to'the surface. It is tobe understoo that the swab head 2 seats in the SerINo. 399,654, filed (Dctober 14,1929.

When the pressure fluid enters below the swab,the inertia of the valve compared with the. area of the lower end of the stem is less than the inertia of the plunger compared withthe'area of its lower end exposed to the pressure fluid. The result is that the valve moves to'closed position before the plunger rises. e

When. the loadof liquid above the swab discharges through its outlet at the upper end of the eduction tube the hunger passes the; opening and the valve is orced open by the will only be closed by the kinetic force of the air, and this is deflected away from the valve stem by the end wall 13. The plunger may thus fall through the air blast, allowing the air to pass the head 2 and through the openings 9 to the interior of the plunger. The stream-line construction of the plunger is such as to offer a minimum of resistance to the passage of the air. The deflector formed by the lower wall 13 around the chamber 15, thus avoiding the dynamic force of the air upon the end of the stem 12, is an important feature of my invention. The openings 1st allow only the static air pressure to affect the valve to cause it to close. The rush of air past the openings 14 and the upper end of the valve has a slight effect to maintain a suction to hold the valve open.

Vhat I claim as new is:

1; A swab construction including a cylin-, drlcal body, a head of smaller d1ameter than said body, said head including a ring having a valve seat on its lower side, a valve below said seat, a stem on said valve, and means to deflect the flow of fluid away from said stem and said valve.

2. A swab construction including a cylindrical body, a head having a ring engaging said body, a portion of smaller diameter than said ring below said ring, a. valve seat on said ring, a valve below said seat, a valve stem slidable in said head, and a deflector below said stem to prevent the dynamic force of fluid passing said swab from moving said valve to closed position.

3. A swab construction including a cylindrical body, a head having a ring engaging said body, a portion of smaller diameter than said ring below said ring, a valve seat on said ring, a. valve below said seat, a valve stem slidable in said head, and a wall enclosing the lower end of the opening in which said stem slides, said wall having lateral openings to allow entrance of static fluid pressure below said valve stem.

i. A swab for wells including a cylindrical body, a valve seat below said body, a valve below said seat, a downwardly directed valve stem on said valve, means to support said valve, and means to deflect the flow of fluid away from the lower end of said valve stem.

but allowing the admission of static pressure fluid thereto.

5. In a well swab, a cylindrical body fa valve seat, ahead of smaller external diameter below said seat,.said head having an upper valve recess and a guide passage below said recess, a valve in said recess, a stem on said valve in said passage, and a chamber below said stem having laterally directed openings therein.

In testimony whereof, I hereunto aifix my signature, this the 19th day of July, A. D.,

HAROLD WV. FLETCHER. 

